Glassware lehr



June 2, 1942.. D. A 3.. MERRlLL GLASSWARE LEHR 7 Sheets-Sheet l Filed Feb. l2, 15241 Inventor. Donald GMerrz'Zl mm m pui.

, June 2, 1942 D. G. MERRILL i 2,284,8:32

GLAsswARE LEHB l Filed Feb. 12, 1941 fr sheets-sheetV 2 In ven for:l anald GMerril Wi'ness: f d ZM( mmm y Affomgg? June 2, 1942 A D. G. MERRILL t 2,284,832

GLASSWARE LEHR Filed Feb. 12, 1941 7 sntS-sheet s` l 1E; Illraiil 52 .In ven tor: l Donald G.Merrz'll Wz'zness: Y i

` June 2, 1942. D. G. MERRILL 2,284,832

` GLAsswARE LEHR Filed Feb. 12, 1941 '7 Sheets-Sheet 4 In c en for: Don ald LvMezjrl'll Witness: y l @Mr/M Attorney@ 7 Sheets-Sheet `5 GLASSWARE LEHR D. G. MERRILL Filed Feb. 12, 1941 Innen for.' Donald GMejrrilI 'y @W Ta/444 A Horn gys.

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June 2, 1942.

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Q. ,iS/mm June-2, 1942. D. G. MERRILL GLASWARE LEHR Filed Feb. 12, 1941 7 Sheets-Sheet 6 In v en tor: Danald GMerrz'll Witness MM A orn 193.

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June 2, 1942. D. G. MERRU; 2,284,832 i GLAS SWARE LEHR Filed Feb. 12, 1941 7 SheetS-Sheet '7 il Donald aMerrilz Witness:

. #fn/n Patented June 2, 1942 UNITED rSTATES PATENT OFFICE GLASSWARE LEER Y Donald G. Merrill, west Hartford, conn., assigner to Hartford-Empire Company, Hartford, Conn., a corporation oi Delaware Application February 12, 1941, Serial No. 378,498

y 17 Claims. (Cl. 49.4'l)

The presentv invention relates to alehr for anhealing or re-annealing glassware and more particularly to a lehr through which decorated Ware may be passed for the fusing thereunto of a ceramic type decoration at a relatively high temperature and for subsequent re-annealing of the ware. `The present invention provides improvements on the lehr of my copending application,

.Serial No. 206,344, filed May 6., 1938, of which the present application therefore may be said to be a continuation in part and which has become Patent 2,244,113. As in the' case of the invention of my aforesaid prior application, Serial No. 206,344, the present invention provides a glassware lehr comprising aplurality of zones including a preheating' zone, a high temperature zone 4Jfor the fusing ci the decoration on the article of glassware, a rapid cooling zone, and a subsequent re-annealing zone which in turn may be subdivided into a slow cooling zone and a zone wherein the cooling is accelerated. The present invention provides novel means for heating the lehr tunnel and for causing circulations and recirculations oflgaseous media therein so as to eifct a gradual transition from predominately lateral recirculations in the lehr at the high temperature zone thereof to predominately longitudinal recirculation ofV gaseous media at the ware-enteringend of the lehr-.tun-

nel.

A further object of the present invention is to provide effective means in this transition zone, as it may be called, for controlling, at least initially, the angular direction of the flames from the burners in this zone. diagonally disposed baille means for directing Such means may include 7 portions ofthe gases being circulated toward the side walls of the tunnel so as to oppose the normal heat losses through the side Walls and so as lateral side walls of the lehr. The arrangement provides for desirable distribution of heat to the particular and novel means in the high temper' ature zone of the lehr tunnel to control the that portion of the lehr. Such control means may includev a damper, accessible from outside the lehr tunnel during the operation of the lehr,l

amount of gases drawn from the tunnel into an `upper combustion chamber which is provided 1n chamber.

for. controlling the amount of tunnel atmosphere recirculated through the upper combustion tween this chamber' and the tunnel proper so as to diffuse the gases passing from the chamber into the tunnel and thereby to prevent the establishment of a hot-spot at a place immediately under an outlet vfor gases from the upper combustion chamber into the tunnel or at any other particular place adjacent to the upper combustion chamber.

lA further objectfof` the present invention is to provide independence of control between/the air supplied to the interior of the tunnel in the rapid cooling` zonefollowing the high temperature or fusing zone in respect to air similarly supplied to the preheating zone. The present invention may provide separately controllable pipes for supplying air `to these zones of the tunnel or separate pipes may be connected to receivevair from a common source subject to two controls, one of the total amount of air from the common source and the other of the proportion oi such total air distributed to the different zones of the end of the tunnel and the ystructure associated with such table, including a portion of the endless lehr conveyor belt and its driving mechal nlsm;

Fig. 3 is a horizontal section with parts broken away, showing the construction of the heating means adjacent to the forward or .ware entering end of the lehr;

Fig. 4 is a transverse Vertical section of the lehr taken on the line 4-4 of Fig. 1;

Fig. 5 is a view in horizontal section similar to Fig. 3 but taken at a point further down the lehl` in the transition zone between the longitudinal recirculation zone and the zone in which the circulations are predominately lateral Fig. 5A is a fragmentary detailed view illustrating the construction of oneV of the burner nozzles shown in Fig. 5 and elsewhere;

on the line ill- I Il of Fig. 2;

Fig. l1 is a fragmentary detail view principal- 1y in longitudinally vertical section, illustrating a portion of the upper fire box, the burners therefor and the means for controlling inflow of tunnel atmosphere thereto adjacent to the burner;

Fig. 12 is a view showing a portion of the upper fire box construction taken in horizontal section substantially on the line I2--I2 of Fig. 11;

Fig. 13 is a fragmentary detail view taken in Vsubstantially longitudinal vertical section, illustrating a portion of the rapid cooling zone and the rear end portion of the upper fire box;

Fig. 14 is a fragmentary detail view in horizontal section taken substantially on the line |4-I4 of Fig. 13; A

Fig. 15 is a fragmentary detail view on an enlarged scale and in transverse vertical section taken substantially on the line l-I5 of Fig. 13;

Fig. 16 is a fragmentary detail view taken substantially in longitudinal vertical section, illustrating the interior construction of the proportioning valve shown in Figs. 13 to l5;

Fig. 17 is a' fragmentary longitudinal vertical section showing a portion of the lehr tunnel and a second form of mechanism for supplying air to the rapid cooling zone and the preheating zone of the'tunnel, and

Fig. 18 is a plan view of the structure shown in Fig. 1'7.

A lehr embodying the present invention comprises an elongate tunnel structure substantially as shown in Figs. 1 and 2, considered together, and' as indicated generally at 20 in these views. Except as to particular features of novelty in connection with the present invention which will hereinafter be described in detail, the structureof the walls of the lehr tunnel need not be described herein other than to state that the manner of constructing these walls, the materialsl therewith, hereinafter to be more particularly described, are such that the lehr comprises or provides a longitudinal series of zones, substantially as follows. A preliminary heating zone A extends from the lware entering or forward end of the lehr tunnel to a vertical transverse plane at about the line indicated at 2| in, Fig. 1. A high temperature zone for fusing or maturing ceramic decoration on the glassware passing through the lehr tunnel extends longitudinally of the lehr from the vertical line 2l to approximate- 1y the plane indicated by-the line 22 in Fig. 1, this zone being designated B. A rapid cooling zone C extends from the line 22 for a short distance along the lehr tunnel, as to the line indicated at 23 in Fig. 1. A re-annealing and relatively slow cooling zone D extends longitudinally of the lehr fromthe-line 23, Fig. 1, to approximately the lehr tunnel, in the zone A, as shown in Fig. 1.' A second dampered stack, indicated at 21 in Fig.

1 may be provided at the top of the lehr tunnel near the rearward end of the zone A. The lehr tunnel may be provided Awith a top re box 28 in the high temperature zone B, as shown in Fig. 1 and partially in Figs. 1l and`12.

IThe lehr tunnel comprises a longitudinally extending main chamber or passageway 29, Figs. 1 and 2, through which the ware is transported while it is undergoing treatment. The upper reach 3l) of an endless flexible openwork conveyor belt 3| extends through the chamber 29 of the lehr tunnel, being supported on an openwork frame structure 32, and provides a means for supporting the glassware to be treated in the lehr tunnel and for transporting such glassware through the lehr tunnel.

This conveyor belt, the means for and manner The tunnel structure is formed to provide be-' neath the main chamber or passageway 29 a subspace or sub-chamber 33 extending from the forward or ware-entering end of the lehr tunnel for a substantial part of the length of the tunnel, as through the zones A, B, C and D, Figs. 1 and 2. Various heating provisions and means for controlling the direction of products of combustion and circulating gaseous media in the lehr tunnel are provided in this sub-chamber and function to provide desirable uniformity of temperature throughout any given transverse plane in the lehr tunnel and a desirable temperature gradient or vcurve longitudinally of this portion of the lehr tunnel. The heating and air circulating and directing provisions in the sub-chamber of the tunnel will now be more particularly pointed out.

'I'he portion of the sub-chamber 33 extending from the forward or ware-entering end of the tunnel for part ofthe length of the zone A, as approximately half of this length, may be used for the reception of a plurality of longitudinally spaced batteries or banks 34, 35 and 36, respectively, of transversely spaced forwardly directed burner nozzles 31, some of which are shown in Figs. 3 and 4. These burner nozzles are provided with suitable fuel mixture, as by supply pipes 38, Figs. 3 and 4. Flames from these nozzles are directed forwardly in passages 39, best'seen in 3. These passages are covered adjacent to and in advance of` the burner nozzles by transversely extending refractory baffles 40, Figs. 1 and 3,v

serve to induce liow of gaseous media from the tunnel chamber 29 through the` ports 42 ,and forwardly in the portion of the sub-chamber 33 in i which the batteries of burner nozzles Neurolocated, substantially as shown bythe arrows in this portion of Fig. 1.

Tu advance of1 each battery of burner nozzles l31 and forwardly of the transverse refractory baffles 40 are longitudinally spaced upwardly and forwardly inclined refractory bottom baflles 43.

(See Figs. 1 and 3.) The foremost of these bottom baflles 43 functions to direct the commingled re-circulating gaseous'media from the tunnel chamber 29 andtheproducts of combustion from the burners 31 upwardly through front outlets 44, controlled by dampers 44a, Figs. l

and 3, into the extreme forward portion of the tunnel chamber 29, whence such gaseous media may pass upwardlythrough the conveyor belt and around theware on such belt to the tstack 26.'

tunneL burner assemblies may be pro- It may be desirable to provide forfgradually` more lateral or transverse circulatory movements of gaseous media in a further portion of the lehr tunnel. To this endfthe portion of the subchamber 33 following that which `contains the. batteries of forwardly directed burners,` above described, may be used to house longitudinally spaced assemblies 45, 46, 41, and 49 (Fig. 1)

of burners. These individually` are located to dischargev products of combustion diagonally to the direction of lengthof the tunnel 'at angles j to ,such direction of length which are predetermined and selectedy when' the burners are installed. Each of these burner` assemblies 45 to 49, inclusive, may comprise two or Vmore burner nozzles 50, each mounted for horizontal swinging adjustment about theaxis of a short vertical pipe connection or` nipple 5| by'which the burner nozzle is operatively connected with a fuel supply pipe 52. (See Fig'` 5A.)` At the'tlme of installing the burner assemblies to49, inclusive,

each burner nozzle,- 50 is adjusted laterally about the'axis of its pivoltalconnection with its supply pipe until it is directed at the desiredkangle to one of the side walls of the lehr tunnel. The nozzles of each such assembly `of burners are then encased in a plastic body of heat insulating and resistant material 53 which will harden and retain the burner nozzles tions.

The burner nozzles 50 discharge products of in their pre-set posiof combustion and gaseous. media may move upcombustion diagonallyA toward the side walls of the tunnel beneath' horizontally disposed bafiies 54, Figs. l. 5 and 6. These .baflles 54 supplement metallic members 55, best seen in Figs. 5 and 6,

which form the cover structure of the portion of the sub-chamber 33 in which the longitudinally spaced burner assemblies 45 to 49. inclusive, are disposed.v Ports are provided at .intervalsadjacent to the baille assemblies,. as at 56, Figs. 1 and 5, for the indraftof gaseous media from the tunnel to this portion of the .sub-chamber of the tunnel.

Refractory baffle blocks 51 are placed within this portion of the sub-chamber 33 of the tunnel in .predetermined relations to the burner nozzles 50 to direct the products of combustion from theseburner nozzles and entrainedgaseous media from the tunnel diagonally towardthe side walls of the tunnel at the angles desired. Atfthe side walls of the tunnel, the products of combustion and entrain'ed gaseous media from the tunnel may pass upwardly through vthe side spaces 58 to the tunnel chamber 29, thus providing diagogases in this porassemblies of burners and dilerent spacings between adjacent batteries and assemblies of burners maybe employed.

In the Anext portion of the sub-chamber 33 of thelehr tunnel which, in the example shown, extends through the zones C and D, the burner assemblies may be such that the circulations of gaseous media in this portion of the tunnel will be predominately lateral or transverse ofv the vided in-this portion of the tunnel as indicated 3.13.59, 60, 6| and 62, respectively, in the final `portion ofFig. 1 and a vportion of Fig. 2. As

shown best in Fig. v7, each of these burner assemblies may comprise four Vburner nozzles '63 spaced angularly around -the verticalV axis of the burner 4assembly head 64 so that two of such burners discharge ina slightly forward direction although mainly toward the side walls of the tunnel while the other two burner nozzles discharge in a slightly rearward direction but also mainly toward the side walls of the tunnel. Each of these nozzles 63 discharges flames and prod-k ucts of combustion through a passage 65. which maybe of Venturi shape. This passage leads to a side .port or opening 66 through which products.

wardly next to va side wall of the tunnel into the overlying main chamber 29.

` The sub-chamber in which the burner assemblies 59- to 62 inclusive are located may be covered by suitable .refractory slabs or members,

which together make up a cover structure designated B1. This cover structure is open transversely of the sub-chamber at the places at which the burner assemblies 59 to 62 inclusive are located, asin'dicated at 68, Fig, '7, so that-gaseous media from the tunnel may be drawn downwardlyvaround the burner nozzles by the inductive action of such nozzles and re-circulated in a direction that is mainly lateral or transverse of the tunnel by the moving products of combustion from the burner nozzles.

The top re box 28, in the zone B. may bev provided With a bottom structure made of metallic panel members. as indicated at 69 yFigs. 1, 11 and 12. At the rearward end of"1his bottom structure, the metallic panel member includedl therein may be provided with a `plurality of transversely spaced openings 10. constituting the intake port to the top combustion chamber from the tunnel chamber 29. A slidable control member, inthe form of a plate 1I. may be moved on this apertured panel member containing the openings 1D so as Ato cover these openings more; or less and thereby to regulate the intake of gaseous media from the tunnel 29f to the top fire box. As shownin Fig. 12, an opening `l2 is 'provided in a side wall of the .lehr tunnel through which a suitable implement, not shown, may be projected and manipulated to slide the plate 1l rearwardly (toward the bottom of Fig. 1g) from its fully opened position to cover the intake openings to the extent desired. The opening 12 in the side wall of the lehr tunnel may be closed when not used for this purpose.

The metallic bottom structure 69 of the top re box may be provided with a series of exhaust apertures 13 in its forward portion, Figs. 1, 11 and 12, so that products of combustion and circulating gaseous media will be directed into the tunnel at a number of spaced points and thus diffused in the tunnel atmosphere so as to avoid a hot spot at any one particular point, as at -the extreme forward end of the combustion chamber.

'Ihe heating of the top fire box may be effected by a battery of transversely spaced forwardly directed burners, one of which is indicated at 14 in Figs. 1 and l1. This battery of burners may be located in the rearward portion of the top combustion chamber above the intake openings 10.

The cooling provisions of the lehr will now be more particularly described. At a forward portion of the zone E, the lehr tunnel may be provided with a controlled air intake port 15 in its bottom and a regulably controlled air intake port 16 directly overhead. These ports may be kept closed or opened as desired. These ports may be connected by side -cooling ducts or wall passages 15a, Figs. 1 and 10. y

The remaining or cooling portion of the lehr tunnel may be provided with top cooling provi- ,sions indicated generally at 11, Fig. 2, including the air blowing mechanism 18. These specic provisions and their functions are the same as in the lehr of my aforesaid application, Serial No. 206,344, and hence need not be described herein.

In the lehr ofthe present invention, separately controllable means are provided for supplying air to the upper corner portions of the lehr tunnel in the rapid cooling zone C and in the preheating zone A.

In one form of mechanism, a pair of air pipes 19 enter the top of the lehr tunnel at the corner portions thereof at places which may be in the cooling zone E (see Fig. 2). These pipes 'extend forwardly in the upper corner portions of the tunnel through the zones D, C, B and in the zone A nearly to the stack 2B, being supported by suitable brackets or hangers which may be of any suitable construction. The pipes 19 are closed at their forward ends and are provided with lateral orifices 8U in the portions thereof in the preheating zone A for discharging jets of air inwardly or toward the longitudinal median line of the tunnel. y

A baffle 8l, which may be substantially trapezoidal in cross-section, as shown in Fig. 4, may

be provided at the top of the lehr tunnel in the preheating zone between the pipes 19 for directing the jets .of air from the latter downwardly at the central portion of the tunnel, thus aiding in effecting transverse circulatory movements of the gaseous media in the tunnel and in diffusing the preheated air from the pipes 19 throughout the gaseous products previously in this portion of the tunnel.

The pipes 19 receive cooling air from branch pipes 82, Fig. 10, of a pipe 83 which is connected with the discharge side of an air blower 84 (Fig. 2). Each of the branch pipes 82 is provided with a damper or valve (Figs. 2 and 10), so that the volume of air passing to each of the pipes 19 may be independently regulated.

A top baflie 86 isprovided between the pipes at the upper part of the tunnel in the rapid cooling zone C, as shown in Figs. 1 and 8. Also, in this rapid cooling zone are provided short pipes 81, respectively located in the upper corner portions of the lehr tunnel. Each of the pipes 81 is connected at its rearward end by a proportioning valve 88 with the adjacent pipe 19. Each pipe 81 is closed at its forward end and is provided with lateral jet openings or Anozzles, best seen at 89 in Fig. 13, for projecting Jets of air inwardly and forwardly toward the baffle 8B in the rapid cooling zone C. As shown in Figs. 15 and 16, the proportioning valve 88 includes a pivoted valve member or gate 99 which may be swung angularly about the axis of its pivotal support 9i to a position to completely cover the bore of the pipe 81, as shown in Figs. 15 and 16, or to a position to completely cover the bore of the pipe 19 or to any intermediate position. The function' of this proportioning valve is to distribute between the two pipes the total amount of air permitted to pass into the pipe 19 from the branch supply pipe 82, this in turn being controlled by the setting cl' the valve 85 in the branch pipe B2.

In the form of structure shown in Figs. 17 and 18, air pipes 92 enter the top of the tunnel and extend forwardly in the upward corner portions thereof similarly to the pipes 19. These pipes 92 receive air from branch pipes 93, provided with valves 94 and connected by pipe 95 with the exhaust side of a blower fan 96. The portions of the pipes 92 in thepreheating zone (not shown) are, of course, provided with the lateral discharge orifices or jet openings, similar to those of the pipes 19. Short pipes 91 are provided in the rapid cooling zone C, these being provided with lateral discharge orices or nozzles 98 similarly to the pipes 81. The pipes 91 have independent connections through the top of the tunnel, by means of branch pipes 99, with a supply pipe |00 which is connected with the outlet side of the blower fan. Valves IUI are provided in the branches 99. With this form of construction, the control of the air supplied through the short pipes in the rapid cooling zone is entirely independent of the control of the air supplied through the pipes 92. The volumes of air supplied through these respective pipes thus may be independently regulated. The air supplied through the air pipes 91 may be cooler than that obtained by the previous form of mechanism in that air is supplied directly to the short pipes in the rapid cooling zone without undergo/ing preheating as in the first form of mechanism.

The air jets from these pipes may have a cooling function in the rapid cooling zone as Well as aiding in effecting desirable circulatory movements of the tunnel atmosphere. In the preheating zone, the air jets may serve primarily to aid circulation of the gaseous media therein but may have some heating effect.

The invention is not to be limited to the specie details herein described as various modifications and changes may be made by those skilled in the art.

1. A lehr for decorating glassware, comprising an initial or heating up zone in which glass is raised from substantially room temperature to adjacent tothe rear portion of said zone constructed and arranged to maintain predominant- 1y lateralv recirculations in the lehr tunnel in paths. moving upwardly adjacent to the side walls of the'tunnel and downwardly adjacent to the longitudinal median portion thereof, and intermediate heating means disposed along said zone of the `lehr tunnel between the first and second named heating means and constructed and arranged-:to establish and, maintain circu' latory currents of heating gases in the lehr tunnel in a gradual progression from the longitudinal recirculation toward the front end of the tunnel to predominant lateral recirculations toward the second named heating means.

v2. Apparatus in accordance with claim 1, wherein said intermediate heating means comprises a plurality of longitudinally spaced groups of burners directed at predetermined angles in respect to the longitudinal center line of the tunnel and located `below the path of the ware therethrough.

3. Apparatus in accordance with claim l, wherein said intermediate heating means comprises a plurality of longitudinally spaced groups of burners located below the path of the ware through the tunnel, each burner group compris` ,4

ing a plurality of nozzles and` symmetrically disposed across the tunnel and wherein each of said nozzles is directed and arranged for independent initial or set-up adjustment of the angle thereof in respect to the longitudinal axis of the lehr tunnel. Y A Y 4. Apparatus in accordance with claim l, wherein said intermediate heating means com-- prises a plurality of longitudinally spaced burners in said tunnel below the path of the ware therethrough which are constructed and arranged'to direct flames in paths, each having a substantial component longitudinally of the tunnel, and two longitudinally disposed sets of spaced inclined baffles for deflecting portions of the gases traveling longitudinally of the tunnel beneath the ware path toward the side walls of thev tunnel.

5. A lehr for decorating and reannealing glass.- ware, comprising an elongate tunnel, means for moving the glassware therethrough, a zone in said lehr in which decorating material is fused on the ware including a top heating means, said heating means comprising a combustion chamber in the top of said tunnel, panel members substantially separating said combustion chamber from: the interior of said tunnel b-ut providing a transversely extending opening between said tunnel and the interior of said combustion chamber at a portionof the latter spaced from the end of the lehr through which the ware enters, and also providing an exit opening between said combustion chamber and the interior of said tun- 'nel adjacent to the end o f said combustion chamber adjacent tothe first named opening and constructed and arranged to direct products of combustion in said combustion chamber in a direction toward the forward end of the lehr through which the ware enters, said panel members having apertures therein to permit more 'of the products of combustion to flow from said combustion chamber into the 'tunnel so as to diffuse the heating effect of said combustion chamber and tov prevent the establishment of a hot spot in said tunnel adjacent to said exit opening.

6. A lehr for decorating and reannealing glassware, `comprising an elongate tunnel, means for `moving the glassware therethrough, a zone in said lehr in which decorating material is fused on the ware including a top heating means, said heating means comprising a combustion chamber in the top of said tunnel, panel members substantially separating said combustion chamber from the interior of said tunnel but providing a transversely extending opening between said tunnel and the interior of said combustion chamber at a portion of the latter spaced from-the end of the lehr through which the ware enters, and also providing an exit opening between said combustion chamber and the interior of said tunnel adjacent to the end of said combustion cham ber towardsaid end of the lehr, burner means in said combustion chamber adjacent to the first named opening and constructed and arrangedv to direct products of combustion in said combustion chamber in a direction toward the forward end of the lehr through which the ware enters, and means for adjustably controlling the amount of gases drawn from said tunnel into said combustonchamber through the rst named opening by the inductive effect of the burner means in said combustion chamber.

7. A lehr in accordance with claim 6, wherein the last named means comprises a damper movable longitudinally of the lehr, an opening through the lateralA side of the lehr tunnel through which said burner means may be ignited and for inspection of the combustion in said combustion chamber, this opening also providing access to said damper and for the adjustment thereof from outside the lehr.

8. A decorating lehr comprising an elongate tunnel, means for moving glassware therelthrough, said tunnel comprising aplurality of zones including a preheating zone, 'a zone for fusing the decoration in the glassware, a rapid cooling zone and reannealing zone, means for supplying heat to the tunnel in each of said zones, a pipe passing along said tunnel from a point in the reannealing zone to the forward portion ofthe preheating zone and having openings therethrough in said preheatng zone, a pipe in said rapid cooling zone extending longitudinally thereof having openings through which air may be supplied into said tunnel, means to supply air to said pipes, and means for independently controlling the amount of air supplied to each of said pipes. Y

9. A lehr in accordance with-claim 8, wherein the means for supplying air to said pipes comprises a common means supplying air to both said pipes, means for controlling theamount of air so supplied, and an adjustable proportioning valve for predetermining the proportion, of the air supplied as aforesaid which will pass to each' of said pipes and thence through the apertures therethrough into the tunnel.

l0. In a lehr, an elongate tunnel having a longitudinally extending main chamber or passage-v way through which glassware to be treated may be transported and having a sub-chamber extending, beneath this main chamber from thel forward end of the lehr for part of the length thereof, forwardly directed burners in said subchamber in a portion ofthe latter adjacent to the front of the lehr, horizontal baffles in adof the sub-chamber nearest to the ware-receving end of the lehr, burners in a more lrearward portion of the sub-chamber for directing products of combustion toward the side walls of the lehr tunnel in directions more lateral than forwardly in the tunnel, and other burners located in the sub-chamber intermediate said rst named and said second named burners for directing products of combustion diagonally toward the side walls of the tunnel at .predetermined angles intermediate the forward directions of the rst named burners and the more nearly lateral directions of the second named burners.

12. In a lehr, an elongate tunnel through which ware may be transported for treatment therein, said tunnel having a sub-chamber beneath the path along which the ware may be moved, forwardly directed burners in a portion of the sub-chamber nearest to the ware-receiving end of the lehr, burners in a more rearward portion of the sub-chamber for directing products of combustion toward the side walls of the lehr tunnel in directions more nearly lateral than forwardly in the tunnel, other burners located in the sub-chamber intermediate said rst named and said second named burners for directing products of combustion diagonally toward the side walls of the tunne1 at predetermined angles intermediate the forward directions of the first named burners and the more nearly lateral directions of the second named burners, and baf-A fles located in said sub-chamber in association with said last named burners for aiding in controlling the direction of movement of products of combustion from said last named burners toward the side walls of the lehr tunnel.

13. In a lehr, an elongate tunnel having successive preheating, high temperature, and rapid cooling zones, air conducting means extending in the tunnel past said rapid cooling zone,`said high temperature zone and into said preheating zone, said air conducting means being adapted to introduce air into the tunnel in said preheating zone, and other air conducting means in said rapid cooling zone of the tunnel for introducing' air into that portion of the tunnel.

14. In a lehr, an elongate tunnel having successive preheating, high temperature, and rapid cooling zones, air conducting means extending in the tunnel past said rapid cooling zone, said high temperature Zone and into said preheating zone said air conducting means being adapted to introduce air into the tunnel in said preheating zone, other air conducting means in said rapid cooling zone. of the tunnel for introducing air into that portion of the tunnel, and means for independently controlling the volumes of air supplied to the respective air conducting means.

15. In a lehr,- an elongate tunnel having successive preheating, high temperature and rapid cooling zones, a pair of air conducting pipes extending in the upper corner portions of said tunnel through said rapid cooling and high temperature zones and into said preheating zone, said pipes having lateral orices in the preheating zone for discharging jets of air into the tunnel at said zone, other air conducting pipes located in the upper corner portions of the rapid cooling zone of the tunnel and provided with lateral orifices for discharging air into the tunnel at this zone, and means for regularly controlling the amounts of air supplied to said first named pipes and to said second named pipes, respectively.

16. Ay glassware lehr comprising an elongate tunnel, means for moving glassware through the tunnel, and means for establishing and maintaining a longitudinal circulation of gases within a portion of the tunnel adjacent to the forward or ware-entering end thereof, comprising a plurality of longitudinally spaced forwardly directed burners disposed in said portion of the tunnel adjacent to the floor thereof, a cover structure for said burner partly separating the interior of said portion of the tunnel into an upper passageway for the glassware and a sub-chamber therebeneath containing said burners, said cover structure having openings therein above and adjacent to the respective burners through which gases may be drawn downwardly from said upper passageway in to said sub-chamber by the inductive action of said burners and having a more forwardly located opening therein for discharging gases from said sub-chamber into said upper passageway, refractory baiiles in said sub-chamber beneath said first named openings in said cover structure and above the level of saidburners, and upwardly and forwardly inclined baiiles located at a lower level in said sub-chamber in advance of said first named bailes and substantially in line with said burners.

17. Apparatus in accordance with claim 16, wherein each of said burners comprises a plurality of transversely spaced nozzles symmetrically arranged in respect to the longitudinal center line of the lehr tunnel.

DONALD G. MERRILL. 

